共查询到20条相似文献,搜索用时 31 毫秒
1.
《Baosteel Technical Research》2010,(Z1):64
Based on the ABAQUS explicit dynamic simulation platform,the finite element model of single stand mill with restrained mandrel was adopted to research the influence of mandrel - roller velocity ratio (MRVR),mandrel friction and tension between stands on rolling force.The analysis results show that when the MRVR is lower than 1,the rolling force increases obviously with the increase of MRVR and reaches the peak value when the MRVR is about 1.The rolling force increase induced by the MRVR increase is the main reason of the formation of the bulge defect on the tube head and tail at the entering and exiting stage during tube continuous rolling process by full floating mandrel mill,which can be intensified by the increase of mandrel friction coefficient.The rolling force decreases with the increase of tension.As the tension is larger, the rolling force decrease amplitude is larger.The influence of backward tension on rolling force is greater than that of forward tension distinctly.Tension control can be used to decrease the rolling force increase induced by the MRVR increase,which is imposing tension at the same time when the MRVR increases,in order to improve even eliminate the bulge defect,and enhance the tube dimension precision. 相似文献
2.
论无缝钢管生产重组与连轧管厂的技术改造 总被引:1,自引:0,他引:1
分析了欧美、日本一些国家的无缝钢管生产重组情况,提出了以生产重组与技术改造相结合的方式重组全浮动芯棒连轧管厂的生产并发展与国际接轨的结构用管(HSS)生产的想法。 相似文献
3.
4.
摘要:为了解决CPE顶管机组轧制薄壁无缝管实际生产中出现的管壁拉凹问题,基于某钢管公司114mm CPE顶管机组的装备和工艺条件,借助于有限元分析软件Simufact,对42CrMo4钢管典型规格111mm×435mm顶管过程的辊模力、各机架轧件出口壁厚、应力应变及相对滑动速度进行了分析。结果表明,顶管过程中,减壁量较大的机架之间存在张力作用,机架减壁量越大,轧件在辊缝处壁厚减薄量越大;轧件在辊缝处所受到的轴向应力均为拉应力,在靠近轧件头部一段距离内轧件所受到的轴向拉应力较大,发生壁厚拉凹的倾向性增大。机架过大的减壁量和减壁率引起的轧件沿孔型宽度方向的严重不均匀变形、机架间大的张力及芯棒与轧件间过大的速度差引起的芯棒拽入力是顶管过程管壁拉凹缺陷产生的主要原因。 相似文献
5.
摘要:针对自动轧管机轧制薄壁不锈钢管中出现的严重横向壁厚不均问题,借助于三维有限元分析软件Simufact,对X10CrNiTi18不锈钢管典型规格112mm×4.5mm自动轧管过程进行数值模拟。研究了不同轧辊孔型结构参数、芯棒润滑状态、轧辊孔型磨损及穿孔毛管偏心对自动轧管横向壁厚精度的影响。结果表明:随着芯棒摩擦因数的增大,所轧荒管横向壁厚精度明显恶化;偏心毛管轧制所轧荒管依旧偏心,延伸轧制对穿孔毛管偏心壁厚纠偏能力有限;磨损的孔型修模后,采用负芯补轧制较增大芯棒直径轧制所轧荒管横向壁厚不均度增大;采用三段式圆弧孔型,所轧荒管横向平均壁厚更接近目标壁厚,横向壁厚不均度由原孔型的13.55%下降到9.94%,横向壁厚精度明显改善。 相似文献
6.
7.
In view of the internal thread defect of thin- walled tubes rolled by Assel 3- roll skew rolling mill, Assel cross- rolling process of X20Cr13 steel tube with typical specification of ??160mm??6. 5mm was numerically simulated by using 3D finite element analysis software Simufact. The influences of different mandrel movement modes, feeding angles and rolling strip profiles on the depth of internal thread were studied. The results show that the depth of the internal thread of steel tube rolled by the full floating mandrel is the most shallow, the second is that of the fixed mandrel and that of the pull mandrel is worst, and it will be gradually deepened when the feed angle increases; the hyperbolic rolling strip is more conducive to controlling the internal thread depth of the rolled tube. Under the condition of hyperbolic rolling strip, the amount of twist deformation of the rolled tube in the rolling process is about 35% smaller than that of the straight rolling strip. 相似文献
8.
9.
10.
In view of serious uneven transverse wall thickness of thin walled stainless steel tube rolled by automatic plug mill,the automatic tube rolling process of X10CrNiTi18 stainless steel tubes with typical specification of 112mm×4.5mm was numerically simulated by using 3D finite element analysis software Simufact. The influence of different roll pass structure parameters, different mandrel lubrication state, roll pass wear and eccentricity of pierced shell on transverse wall thickness accuracy of automatic rolling tube was analyzed. The results show that as the friction coefficient of the mandrel increases, the accuracy of transverse wall thickness of the rolled tube deteriorates obviously. The hollow tube rolled by eccentric pierced shell is still eccentric, and it shows that the elongation rolling has a limited ability to correct the eccentric wall thickness of the pierced shell. With repaired the worn pass, the unevenness of the transverse wall thickness of the rolled tube increases using the negative mandrel compensation rolling compared with the increase of mandrel diameter. The average transverse wall thickness of the rolled tube is closer to the target wall thickness by using three section arc groove, and the transverse wall thickness unevenness decreases from 13.55% of the original groove to 9.94%, and the transverse wall thickness accuracy is obviously improved. 相似文献
11.
12.
Roller pass is one of the key factors affecting the product quality in the retained mandrel rolling process. The metal flow condition of rolling deformation area was researched using the FEA (finite element analysis) software Marc. The influences of the pass bottom radius, the sidewall radius, the sidewall angle, the roller shoulder fillet radius, as well as the roller gap on the rolling process under the conditions of different friction were discussed. Based on these results, the changes of the workpiece exit width, the mandrel axial force, the rolling force, and the rolling torque associated with various parameters were determined, which would provide the basis for designing the pass and determining the rolling condition reasonably. 相似文献
13.
冷连轧高速轧制过程中摩擦因数机理模型的研究 总被引:2,自引:0,他引:2
在现场试验与理论分析的基础上,针对现有摩擦模型对冷连轧高速轧制过程中摩擦因数的预报精度不高、通用性不强等问题,首先对润滑油膜厚度计算模型与摩擦因数返算方法进行了推导,然后定量研究了辊缝中润滑油膜厚度与摩擦因数之间的关系,最终建立起一套适合冷连轧高速轧制的摩擦因数机理模型,并将其应用于宝钢冷轧薄板厂1220五机架冷连轧机与宝钢冷轧厂2030五机架冷连轧机的生产实践.应用结果表明:提高了轧制的稳定性与带材的控制精度,减小了相关模型的自学习与自适应系数波动,取得了良好的使用效果. 相似文献
14.
15.
针对不锈钢冷连轧生产工艺,提出动态变形抗力概念,利用四辊可逆冷轧机和Inston高速拉伸实验机进行轧制-拉伸实验,在MMS-200热模拟实验机上测定不锈钢的应力-应变曲线,建立不锈钢动态变形抗力模型。在Hill方程的基础上建立了轧制力显函数模型,并通过变形抗力和摩擦因数的逆向回归计算实现模型的在线自学习。提出了适合轧制力模型的可信度评估方法,引入Theil不等式系数法,依据TIC值定性分析了模型的适用性。最终确立了适合于冷连轧生产的精确的轧制力显函数模型,并将其应用到生产实践中。统计结果表明:冷连轧过程中轧制力的模型计算值与实测值的相对误差小于3.67%,该模型具有良好的计算精度和较好的泛化能力,适合于工业生产实践。 相似文献
16.
To improve the accuracy of rolling force prediction, some important force models were evaluated through applied computation for cold rolling of low carbon steel and aluminum alloy according to measured data on lab mill. The effects of model structure and three important variables ‐ flow stress, contact length and friction coefficient ‐ on the precision of computed force were quantitatively studied. Flow stress was measured with plane‐strain compression test, contact length was based on elastic flattening of work‐roll by Hitchcock, and friction‐coefficient was determined by rolling strain and numerical iteration. In steel rolling Bland & Ford integration model and Bryant & Osborn algebraic equation are better in accuracy than Ekelund and Parkins. In aluminum rolling all the models produce large deviations ΔFR = 10–20% if flow stress, contact length and friction coefficient are determined with the same method as steel rolling. The elastic deformation of aluminum strip is now taken into account for its low elastic modulus. An effective method to determine plastic and elastic contact has been developed in this investigation. The accuracy of force computation is obviously improved for aluminum rolling. 相似文献
17.
18.
论MPM轧管工艺的发展 总被引:5,自引:0,他引:5
简要介绍了限动芯棒连轧管机经历25年4个阶段的发展简史,对典型的机组进行了评述.PQF轧管工艺的成就标志着MPM轧管工艺的发展完善,也为长芯棒连轧管工艺近百年的历程画上了句号.文章着重提出先进的轧管工艺要与先进的自动控制软件包相配套,强调要重视国产连轧管技术的发展. 相似文献
19.
20.
无缝这生产工艺带头的特点是多种工艺并存。这和无缝钢管生产工艺发展的历史有关,这种并存的局面是一种非稳态,优胜劣汰,势在必特,值得注意的是:就先进的连轧管工艺来说,限动芯棒连轧管工艺发展特别迅速,当前正在向三辊式机架、紧凑式轧机的方向发展。再加上NRE工艺的出现,这种工艺将在种种口径钢管生产中占优势。 相似文献